Aspertaichamide a, a novel cytotoxic prenylated indole alkaloid possessing a bicyclo[2.2.2]diazaoctane framework from a marine algal-derived endophytic fungus aspergillus taichungensis 299.

Filamentous fungi belonging to the genus Aspergillus are prodigious producers of alkaloids, particularly prenylated indole alkaloids, that often exhibit structurally diversified skeletons and potent biological activities. In this study, five prenylated indole alkaloids possessing a bicyclo[2.2.2]diazaoctane core ring system, including a novel derivative, namely aspertaichamide A (1), as well as four known compounds, (+)-stephacidin A (2), sclerotiamide (3), (-)-versicolamide B (4), and (+)-versicolamide B (5), were isolated and identified from A. taichungensis 299, an endophytic fungus obtained from the marine red alga Gelidium amansii. The chemical structures of the compounds were elucidated by comprehensive NMR and HRESIMS spectroscopic analyses. In addition to the previously reported prenylated indole alkaloids, aspertaichamide A (1) was characterized as having an unusual ring structure with the fusion of a 3-pyrrolidone dimethylbenzopyran to the bicyclo[2.2.2]diazaoctane moiety, which was rare in these kinds of compounds. The absolute configuration of 1 was determined by TDDFT-ECD calculations. In vitro cytotoxic assays revealed that the novel compound 1 possessed selective cytotoxic activity against five human tumor cell lines (A549, HeLa, HepG2, HCT-116, and AGS), with IC50 values of 1.7-48.5 µM. Most importantly, compound 1 decreased the viability of AGS cells in a concentration-dependent manner with an IC50 value of 1.7 µM. Further studies indicated that 1 may induce AGS cells programmed cell death via the apoptotic pathway.

Antimicrobial and cytotoxic phenolic bisabolane sesquiterpenoids from the fungus Aspergillus flavipes 297.

Phenolic bisabolane-type sesquiterpenoids (PBS) represent a rare class of natural products with diverse biological activities. In this study, chemical investigations of the fungus Aspergillus flavipes 297 resulted in the isolation and identification of seven PBS, including a pair of new enantiomers (+)-1a and (-)-1b, a new derivative 2, and five previously reported ones 3-7. The chemical structures of the isolated PBS were determined by extensive NMR and HRESIMS spectroscopic analysis. The absolute configurations of the separated enantiomers (+)-1a and (-)-1b were solved by comparison of the experimental ECD spectra with those of the TDDFT-ECD calculated spectra. The new compounds 1 and 2 represent rare cases of PBS bearing a methylsulfinyl group, which was distinct from the commonly-observed PBS structurally. All the isolated compounds 1-7 were evaluated their antimicrobial and cytotoxic activities. As a result, the tested compounds showed selective antimicrobial activity against several pathogenic bacteria and fungi with the MIC (minimum inhibiting concentrations) values ranging from 2 to 64 µg/mL. Moreover, enantiomers (+)-1a and (-)-1b, together with compound 2, exhibited promising cytotoxicity against MKN-45 and HepG2 cell lines, respectively, indicating that the methylsulfinyl substituent enhanced cytotoxicity to a certain degree.

[Decreased expression of CatSper1 in the sperm of varicocele rats and protective effect of L-carnitine].

OBJECTIVE: To investigate the expression of the sperm-specific cation channel (CatSper1) in the epididymal sperm of varicocele (VC) rats and the effect of L-carnitine (LC) on the CatSper1 level. METHODS: Seventy male rats were equally randomized into groups A (normal control), B (VC model control), C (VC treated with normal saline), D (VC treated with low-dose LC), E (VC treated with medium-dose LC), F (VC treated with high-dose LC), and G (VC treated by prolonged medication of high-dose LC). The VC model was established by partial ligation of the left renal vein. At 12 weeks after modeling, the model rats in group C were treated intragastrically with normal saline at 1 ml/kg/d, those in groups D, E and F with LC at 0.05, 0.1 and 0.2 g/kg/d respectively, all for 5 consecutive weeks, and those in group G with LC at 0.2 g/kg/d for 7 successive weeks. Then, all the animals were sacrificed and their epididymides harvested for obtainment of the semen parameters by computer-assisted semen analysis (CASA) and determination of the mRNA and protein expressions of CatSper1 in the sperm by RT-PCR and Western blot. RESULTS: Compared with the rats in group A, those in group B showed significantly decreased percentage of grade a+b sperm (P < 0.01), sperm viability (P < 0.01), sperm concentration (P < 0.01) and expressions of CatSper1 mRNA (1.44 ± 0.67 vs 0.71 ± 0.38, P < 0.01) and protein (1.87 ± 0.67 vs 0.84 ± 0.42, P < 0.01). In comparison with the animals in group C, those in the four LC intervention groups exhibited a markedly increased percentage of grade a+b sperm, sperm viability and mRNA and protein expressions of CatSper1, even more remarkably in groups F and G (P < 0.01). No statistically significant difference, however, was observed in sperm concentration between group C and the LC intervention groups (P > 0.05), nor in the mRNA and protein expressions of CatSper1 between groups F and G. CONCLUSIONS: The expression of CatSper1 is decreased in the epididymal sperm of varicocele rats, and L-carnitine can increase the sperm viability, percentage of grade a+b sperm and CatSper1 expression of the rats.

[Improving effect of Shengjingsan on spermatogenic function following testicular torsion/detorsion in rats and its mechanism].

OBJECTIVE: To study the effect of Shengjingsan on spermatogenic function following testicular torsion/detorsion in rats and its action mechanism. METHODS: Forty SD male rats were equally randomized to groups A (sham operation), B (control), C (low-dose Shengjingsan), D (medium-dose Shengjingsan) and E (high-dose Shengjingsan). The model of testicular torsion was established by 720 degrees clockwise torsion of the left testis for 4 hours. An hour before operation, the rats of group B received daily gavage of normal saline at 1 ml per kg per d, while those in groups C, D and E that of Shengjingsan at 0.01, 0.02 and 0.03 g per kg per d, all for 35 days. Then all the rats were sacrificed for measuring the semen parameters by CASA and detecting the expression of the CatSper1 gene in the sperm by RT-PCR. RESULTS: Compared with group A, Sperm concentration, the percentage of grade a + b sperm, sperm vitality and CatSper1 expression were significantly lower in group B ([15.30 +/- 6.30] %, [44.42 +/- 6.36] %, [21.00 +/- 6.14] x 10(6)/ml and 1.12 +/- 0.50) than in A ([51.30 +/- 6.60]%, [69.01 +/- 7.20]%, [40.53 +/- 7.01] x 10(6)/ml and 2.04 +/- 0.77) (P < 0.01). Compared with group B, the four parameters were increased remarkably in groups D ([51.63 +/- 3.20] %, [72.09 +/- 2.20]%, [55.30 +/- 5.90] x10(6)/ml and 2.11 +/- 0.20) andE ([55.93 +/- 3.17]%, [73.01 +/- 2.11]%, [58.33 + 4.90] x 10(6)/ml and 2.31 +/- 0.17) (P < 0.01), but not significantly in C ([18.02 +/- 0.23]%, [48.04 +/- 7.01]%, [22.87 +/- 2.10] x 10(6)/ml and 1.19 +/- 0.51) (P > 0.05). CONCLUSION: Shengjingsan can improve sperm parameters following testicular torsion/ detorsion in male rats by regulating their spermatogenic function and improving the expression of CatSper1 in the sperm.

[Phosphate transform of composting with pre-mixing insoluble phosphate using high temperature dissolved phosphorus microbes inoculation].

In order to enhance the available phosphorus (P) of compost production, the experimental design of composting included three treatments was conducted. The treatments were: Control (CK) with no dissolved phosphate microbes inoculation, no rock phosphate mixing; CP with no dissolved phosphate microbes inoculation, rock phosphate mixing; CMP with dissolved phosphate microbes inoculation, rock phosphate mixing. At different composting phases, the samples were taken for the determination of phosphorus forms. Compared to CK, organic P, dissolved P and rapidly available P of CP increase by 2 049.8, 264.2, 954.0 mg/kg at final stage of composting, respectively; while that of CMP increase by 4 188.6, 648.7, 3 576.4 mg/kg, respectively. The increase of organic P, dissolved P and rapidly available P in CMP is 2.04, 2.46, 3.75 times as that of CP, respectively. The results indicated dissolved phosphate microbes inoculation composting with pre-mixing rock phosphate would accelerate transform efficiency of insoluble phosphate, increase the available P of compost production.